OAKLAND — After city officials canceled a forum this week on the police department’s response to Occupy Oakland protests, the Occupy movement has decided to hold a forum of its own.

The forum, originally organized by Oakland’s Citizens’ Police Review Board, and slated to take place at City Hall with police officials and attorney James Chanin in attendance, will now be held by Occupy supporters at 6:15 p.m. Thursday at the Grand Lake Theater, a theater manager confirmed late Thursday.

Derrick Muhammad, a police oversight board member, said city officials informed him earlier this week that they had canceled Thursday’s forum over security fears stemming from last Saturday’s protests, during which several demonstrators broke into City Hall and vandalized the lobby.

Muhammad said he understood the city’s concerns and expected the board to hold the forum at a later date.

The civilian oversight board is currently investigating eight formal complaints against police stemming from Occupy events, including the Oct. 25 incident in which U.S. Marine veteran Scott Olsen was struck in the head by a tear-gas canister. The Internal Affairs Division of the Police Department has received about 1,000 Occupy-related complaints.

Occupy Oakland supporter and chronicler Spencer Mills said the group would invite board members, Police Chief Howard Jordan and the public to Occupy’s forum at the theater, located at 3200 Grand Avenue.

Mills said Occupy members would show videos of police responses to protesters over the past four months. “We’re going to do the Citizen’s Police Review Board’s job for them, because they won’t do it themselves,” he said.